Multi-video receiving method and apparatus

ABSTRACT

A method and apparatus is disclosed for receiving a plurality of video signals using a single video signal transmitted using a point-to-multipoint connection; the plurality of video signals originate from various locations of an event. Information received using a reception unit comprises at least one of the plurality of video signals, at least one of the plurality of sound track signals related to the at least one of the plurality of video signals, data transmitted using the vertical blanking interval (VBI) of the single video signal and graphics.

FIELD OF THE INVENTION

This invention relates to multi-video program receiving method andapparatus, and more precisely, to the displaying and access to more thanone video program related to a live event.

BACKGROUND OF THE INVENTION

Assisting to a live event is usually an enjoyable experience as all oursenses are overwhelmed by various sensations. The assisting is thereforemore enjoyable than a remote assisting via a television program relatedto said event. Unfortunately, it is usually difficult to have more thanone view of the event when assisting to said event. This is particularlytrue during Formula I Grand Prix competitions, where a viewer is usuallyseated at a particular point of the circuit. Usually in that case, theviewer cannot have access to other parts of the circuit unless a largescreen is available for instance. This may avoid the viewer to enjoy anaction that is taking place at another location of the circuitunavailable to him.

Various solutions have been implemented in order to enable the viewer atthe live event to access more information about the event.

For instance, in some major car racing events, such as CART/NASCAR,radio scanners are available. Such radio scanners enable the live eventviewer to scan and listen to conversations between a pilot and his crew.Unfortunately the device lacks excitement and entertainment because itonly offers sound, making it difficult for the user to easily understandwho they are listening to and being potentially more disruptive thanenhancing.

Mini portable television sets have been developed and are alreadyavailable on the market. Via such mini portable television sets, thelive event user can watch the race to the extent that it is broadcast,but, in most cases, the live events are broadcast on cable TV and aretherefore inaccessible to these devices. These mini portable televisionsets have therefore limited applications and do not offer the excitementor any added value of the event that would motivate the users to widelyuse it.

Wireless handled devices based on web technology have also beendeveloped. These devices run on PDA and are linked to the web. Suchdevices provide VIP guests and general audience live timing and scoring,radio feeds and background info on team cars, car drivers, golf players,etc. They integrate rich multimedia and interactive interfaces.Unfortunately, these devices lack with many drawbacks. A first drawbackis the fact that the technology is usually implemented using apoint-to-point connection, such point-to-point connection does not allowa massive use of the device at a live event as an important frequencybandwidth would be necessary to serve an important number of users. Suchdevices have a limited effectiveness when delivery video content due tothe limited bandwidth used. Moreover, data compression schemes aremandatory in order to cope with limited bandwidth. It is difficult, inthese conditions, to have a real time transmission of video datastreams. These devices are also very expensive due to the fact that theyare based on an expensive hardware architecture.

There is a need for a method and apparatus to overcome theabovementioned drawbacks.

SUMMARY OF TE INVENTION

It is an object of the invention to provide a method for broadcastingmore than one video program and data to a plurality of reception units;

It is another object of the invention to provide an apparatus forbroadcasting more than one video program and data to a plurality ofreception units using a point-to-multipoint connection;

It is another object of the invention to provide a method for receivingmore than one video program and data transmitted using a wirelesspoint-to-multipoint connection;

It is another object of the invention to provide an apparatus forreceiving more than one video program and data transmitted using awireless point-to-multipoint connection;

According to the above objects, from a broad aspect, the presentinvention provides a method for providing a plurality of video programsto a plurality of video program receivers having a first resolutionusing a single frequency band enabling transmission of a video programhaving a second resolution substantially higher than the firstresolution, the method comprising the steps of receiving a plurality ofvideo programs from a plurality of video program sources, the pluralityof video programs having a resolution substantially equal to the secondresolution; formatting each of the plurality of video programs receivedfrom the plurality of video program sources to have a resolutionsubstantially equal to the first resolution; inserting each of theformatted video programs at a specific location in a main video signalhaving a resolution substantially equal to the second resolution andtransmitting the main video signal to each of the plurality of videoprogram receivers.

According to another broad aspect of the invention, there is provided anapparatus for broadcasting at least one of a plurality of video programsignals inserted in a main video signal to a plurality of receivingunits, each receiving unit having a first resolution, the main signalhaving a second resolution substantially higher than the firstresolution, the apparatus comprising a formatting unit receiving the atleast one of a plurality of video programs signals, the formatting unitformatting the at least one of a plurality of video program signals tohave a resolution substantially equal to a resolution of a receivingunit, the resolution of the receiving unit being substantially lowerthan the resolution of the main video signal, a combining unit,receiving the formatted at least one of a plurality of video signals andincorporating each of the formatted at least one of a plurality of videosignals into a specific location in the main video signal and atransmitter, receiving the main video signal and transmitting the mainvideo signal to the plurality of receiving units.

According to another broad aspect of the invention, there is provided anapparatus for displaying at least one of a plurality of video programsignals inserted in a main video signal, the at least one of a pluralityof video program signals having a first resolution, the main signalhaving a second resolution substantially higher than the firstresolution, the apparatus comprising a receiving unit receiving the mainvideo signal, a user interface for enabling a user to select at leastone of the plurality of video programs contained in said main videosignal for a display, the user interface providing a command signalrepresentative of the selected at least one of the plurality of videoprograms to display, a display screen, receiving the selected videosignal for display and a processing unit receiving the main video signaland selecting at least one part of the main video signal provided by thereceiving unit according to said command signal provided by the userinterface, the selected one of the plurality of video programs todisplay being displayed on said display screen.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentinvention will become more clearly understood with the followingdescription and accompanying drawings, wherein:

FIG. 1 is a diagram that shows a transmitting unit and a plurality ofreception units;

FIG. 2 is a diagram that shows a perspective view of a reception unit;the reception unit comprises a plurality of buttons for enabling a userto control it;

FIG. 3 is a diagram that shows one image of a main video signal; theimage comprises four different images originating from different videosignals;

FIG. 4 is diagram which shows how four sound track signals are embodiedin a single main video signal;

FIG. 5 is a flow chart that shows how various video program signals aretransmitted to a plurality of reception unit;

FIG. 6 shows a block diagram of the preferred embodiments of a receptionunit, the reception unit comprises a tunable receiver, a videodigitizer, a Field Programmable Gate Array (FPGA), a frame buffer, agraphics storage unit, a microprocessor, a user interface, an audiounit, a display unit and an input/output interface;

FIG. 7 is a flow chart that shows how the reception unit operates in thepreferred embodiment of the invention;

DETAILED DESCRIPTION OF DIFFERENT EMBODIMENTS

Now referring to FIG. 1, there is shown the preferred embodiment of theinvention. The system comprises a broadcasting unit 17, a plurality ofsound sources, a plurality of video sources, a data source 24, and aplurality of reception unit 28.

The broadcasting unit 17 comprises a sound formatting unit 18, a videoformatting unit 20, a combining unit 22, a transmitting unit 26.

The sound formatting unit 18 receives a plurality of sound track signalsfrom the plurality of sound sources. The sound formatting unit 18provides a plurality of formatted soundtrack signals. In the preferredembodiment of the invention, the formatted soundtrack signals have aspecific bandwidth as explained below.

The video formatting unit 20 receives a plurality of video signals froma plurality of video sources. The video formatting unit 20 provides aplurality of formatted video signals. In the preferred embodiment of theinvention, the formatted video signals have a pixel resolution of 360 by240.

The combining unit 22 receives the plurality of formatted soundtracksignals, the plurality of formatted video signals, and a data signalprovided by the data source 24. The combining unit 22 combines theplurality of formatted soundtrack signals, the plurality of formattedvideo signals, and the data signals into a single video signal. In thepreferred embodiment of the invention, the combined video signal is aNTSC compatible video signal. Still in the preferred embodiment of theinvention, four sound sources 10 are used, and four video sources areused in order to combine. the video signals. In another embodiment ofthe invention, more than one video sources and more than one soundsources may be used. The transmitting unit 26 receives the combinedvideo signal and transmits the combined video signal in the preferredembodiment of the invention. The transmitting unit 26 operates under theNorth American NTSC broadcast standard, which includes the luminancecarrier, the chrominance carrier, and the audio carrier. The totalbandwidth of the transmitted signal does not exceed 6 MHz. Still in thepreferred embodiment of the invention, the transmitting unit 26 iscapable of covering a range of 3 km, which is necessary to suit theneeds of the application. In the case of an event requiring more alarger coverage, a more powerful transmitting unit 26 may be used.

A plurality of reception units 28 receive a transmitted signaltransmitted using the transmitting unit 26. As explained below, each ofthe reception units 28 are able to receive at least one of the pluralityof video sources and at least one of the corresponding sound sources.

Now referring to FIG. 2, there is shown a reception unit 28. Thereception unit 28 comprises a display screen, which is a LCD displayscreen 96. Still in the preferred embodiment of the invention, thedisplay screen 96 is visible in the light and at night using front lightTFT active matrix technology. The display measures 3.8 inches indiagonal. The display screen 96 has a pixel resolution of 320 by 240.

The aspect ratio of the display screen is the North American TV standard4:3. It will be appreciated by someone skilled in the art that othertelevision standards may be used.

The reception unit 28 comprises a user interface having a plurality ofbuttons. In the preferred embodiment of the invention, the userinterface comprises a power on/off button 30, a back button 32, agraphics menu 34, a volume up button 36, a volume down button 38, a leftbutton 40, a right button 42, an up button 46, a down button 44 and aenter button 48.

The power on button 30 enables the user to switch on, switch off thereception unit 28. The volume up button 36 enables the user to increasethe output volume of the reception unit 28. The volume down button 38enables the user to decrease the output volume of the reception unit 28.The menu button 34 enables the user to access graphics. The back button32 enables the user to access a screen display prior a last command. Theleft button 40, the right button 42, the down button 38, and the upbutton 46 enable the user to navigate in a plurality of menus displayedon the display screen 96. The enter button 48 enables the user toconfirm a selection in a menu displayed on the display screen of thereception unit 28.

Now referring to FIG. 3, there is shown a diagram which presents asingle image of the combined video signal generated by the combiningunit 22. The single image shown in this figure comprises foursub-images, respectively sub-image 80, sub-image 82, sub-image 84 andsub-image 86. Sub-image 80 refers to an image originating from the firstvideo source. Sub-image 82 refers to an image originating from thesecond video source. Sub-image 84 refers to an image originating fromthe third video source. Sub-image 86 refers to an image originating fromthe fourth video source.

In the preferred embodiment of the invention, the pixel resolution ofthe sub-image 80, the sub-image 82, the sub-image 84 and the sub-image86 is 320 by 240.

Now referring to FIG. 4, there is shown how audio is formatted in thepreferred embodiment of the invention.

In the preferred embodiment of the invention, the first sound tracksignal is stored in the main audio channel portion of the combined videosignal, which is referred as the L+R portion of the combined videosignal. Still in the preferred embodiment of the invention, the secondsound track signal is stored in the L−R portion of the combined videosignal; the third sound track signal is stored in the SAP portion of thecombined video signal and the fourth sound track signal is stored in thecue channel portion of the combined video signal. It will be appreciatedby someone skilled in the art that alternatives storing schemes may beused depending on the transmission standard used. Furthermore, it willbe appreciated that the first sound track signal, the second sound tracksignal, the third sound track signal and the fourth sound track signalmay be compressed using a CODEC prior being inserted in the combinedvideo signal. Someone skilled in the art will appreciate thatcompression may provide a higher sound quality.

Now referring to FIG. 5, there is shown a flow chart which shows theoperating of the broadcasting unit 17. According to step 50, a firstvideo signal is provided by a video source. According to step 52, afirst soundtrack signal is provided by a first sound source. Accordingto step 54, a second video signal is provided by a second video source.According to step 56, a second soundtrack signal is provided by a secondsound source. According to step 58, a third video signal is provided bya third video source. According to step 60, a third soundtrack signal isprovided by a third sound source. According to step 62, a fourth videosignal is provided by a fourth video source. According to step 64, afourth soundtrack signal is provided by a fourth sound source. Accordingto step 66, the first video signal provided in step 50, the second videosignal provided in step 54, the third video signal provided in step 58and the fourth video signal provided in step 62 are formatted in asuitable format by the video formatting unit 20 as explained below.According to step 68, the first soundtrack signal provided in step 52,the second soundtrack signal provided in step 56, the third soundtracksignal provided in step 60, and the fourth soundtrack signal provided instep 64 are formatted by the sound formatting unit 18 into a suitableformat as explained below. According to step 70 the combining isperformed using the plurality of formatted soundtrack signal generatedaccording to step 68 and the plurality of formatted radio signalsgenerated according to step 66 and using a data signal providingaccording to step 48. According to step 72, the combined signalgenerated to step 70 is transmitted using the transmitting unit 26.

In an alternative embodiment of the invention, at least one graphicssource may be used instead of at least one video source.

Now referring to FIG. 6, there is shown a block diagram of the receptionunit 28 in the preferred embodiment of the invention. In the preferredembodiment of the invention, the reception unit 28 comprises a tunablereceiver 80, a video digitizer 82, a Field Programmable Gate Array(FPGA) 84, a frame buffer 86, a graphics storage unit 88, amicroprocessor 90, an audio unit 92, a display unit 102, a userinterface 98, and an input/output interface 100. The display unit 102comprises a LCD driving circuit 94 and a LCD screen 96.

In the preferred embodiment of the invention, the LCD screen 96 is aSanyo TMO38QV-67A02A; the FPGA 84 is a Xilinx Spartan II. Still in thepreferred embodiment of the invention, the microprocessor 90 is aMicrochip PIC16F877. The tunable receiver 80 is a Samsung TCPN9081DA10C.The video digitizer 82 is a Philipps SAA7111. The frame buffer 86 is aISSI IS62LV12816L. The graphics storage unit 88 is an AMD 29LV640D.

The combined video signal transmitted using the transmitting unit 26 isreceived by an antenna of the tunable receiver 80. The microprocessor 90sends a selected channel signal to the tunable receiver 80. The tunablereceiver 80 extracts a video signal according to the selected channelsignal. The video digitizer 82 digitizes the video signal received fromthe tunable receiver 80. The FPGA 84 receives the digitized video signalprovided by the video digitizer 82 and stores at least one frame of thedigitized video signal into the frame buffer 86; the digitized videosignal is stored into the frame buffer 86 at a rate of 30 frames persecond in the preferred embodiment of the invention. The FPGA 84 furtherextracts the embedded data comprised in the Vertical Blanking Interval(VBI) portion of the digitized video signal and stores the data in theFPGA 84.

The microprocessor 90 controls the audio unit 92. In the preferredembodiment of the invention, the audio unit 92 comprises an audioamplifier receiving an audio signal received from the tunable receiver80 according to a selected portion of the video signal transmitted inaccordance with the storing scheme presented in FIG. 4. The user mayprovide information using the user interface 98 to the microprocessor90. An input/output interface 100 is connected to said microprocessor 90in order to upload/download information from a remote device.Information downloaded from a remote device may comprise graphics datawhich, after being collected by said microprocessor 90 via saidinput/output interface 100, are provided to the graphics storage unit 88via the FPGA 84. The FPGA 84 provides a video signal to display to theLCD driving circuit 94 of the display unit 102. The LCD driving circuit94 provides a final signal to the LCD screen 96.

Now referring to FIG. 7, there is shown the operation of the receptionunit 28. According to step 110, a configuration set up is performed. Theconfiguration set up 110 comprises the providing of a selected channelsignal to the tunable receiver 80. In the preferred embodiment of theinvention, the reception unit 28 receives simultaneously a singlechannel signal, in an alternative embodiment, the reception unit 28 mayreceive, simultaneously, a plurality of channel signals using aplurality of tunable receivers 80. Still according to the configurationset up, the display unit 102 is carefully tuned by the microprocessor 90via the FPGA 84. According to step 112, the user performs a modeselection. If the user selects the video mode, a first channel isselected according to step 114. According to step 116, video isprocessed by the FPGA 84. More precisely, the FPGA 84 retrieves a framefrom the frame buffer 86. The FPGA 84 descrambles the retrieved frameand provides the video signal to display to the LCD driving circuit 94.The tunable receiver 80 extracts a corresponding audio signal to thevideo signal selected from the corresponding portion of the transmittedvideo signal. The audio unit 92 provides an amplified audio signal,which may be listened by the user using headsets for instance. Theamplified audio signal and the displayed video signal are provided tothe user according to step 118.

If the user selects the graphics mode using the menu button 34,according to step 120, a menu is provided to the user. The menu iscreated using data extracted from the digitized video signal in theVertical Blanking Interface (VBI) portion of the signal and stored inthe FPGA 84 and/or using graphics data stored in the graphics storageunit 88. In the preferred embodiment, graphics are stored using BMP fileformat.

The microprocessor 90 controls the FPGA 84 to generate a video signal tobe displayed which is then provided to the LCD driving circuit 94, thevideo signal to be displayed comprises the above-mentioned data providedby the FPGA 84 together combined with graphics data stored in thegraphics storage unit. According to step 122, the user selects via theuser interface 98 a new data to obtain. In one application of theinvention, the data may be the ranking of a participant of the liveevent, a summary of a part of the event. According to step 124, themicroprocessor 90 controls the FPGA 84 to retrieve data, which is storedin the FPGA 84. According to step 126, the data are provided to the useras explained previously. In the preferred embodiment of the invention,the video signal to be displayed comprises the data as well as graphicsdata retrieved from the graphics storage unit 88 by the FPGA 84. Thevideo signal to be displayed is therefore created by the FPGA 84.

Now referring back to FIG. 1, the sound formatting unit 18 converts thefirst soundtrack signal, the second soundtrack signal, the thirdsoundtrack signal and the fourth soundtrack signal into formattedsoundtrack signals that will be combined and modulated to create acombined video signal having the first soundtrack signal, the secondsoundtrack signal, the third soundtrack signal and the fourth soundtracksignal modulated according to the scheme displayed in FIG. 4. Stillreferring to FIG. 1, the video formatting unit 20 comprises fourdigitizers receiving respectively the first video signal, the secondvideo signal, the third video signal and the fourth video signal andproviding a first digitized video signal, a second digitized videosignal, a third digitized video signal and a fourth digitized videosignal. The video formatting unit 20 further comprises fourinterpolating units respectively connected to the first digitizer, thesecond digitizer, the third digitizer and the fourth digitizer. Thefirst interpolating unit receives the first digitized video signal, thesecond interpolating unit receives the second digitized video signal,the third interpolating unit receives the third digitized video signaland the fourth interpolating unit receives the fourth digitized videosignal. Each interpolating unit dismisses one pixel about twohorizontally and one pixel about two vertically. The first interpolatingunit provides therefore an interpolated image that has a pixelresolution of one about four of the original pixel resolution, theresolution of the first digitized image provided to the firstinterpolating unit. The second interpolating unit, the thirdinterpolating and the fourth interpolating unit operate in the samemanner as the first interpolating unit. The combining unit 22 receivesthe formatted video signals and the formatted soundtrack signals andprovides a combined video signal.

In order to protect the network against eavesdropping and uncontrolleduse, the combining unit 22 further comprises a scrambling unit whichscrambles the combined video signal prior providing it to thetransmitting unit 26; this scrambling unit is not shown in FIG. 1.

In the preferred embodiment of the invention, switching vertical linestwo by two performs the scrambling. The FPGA comprised in the receptionunit is used to descramble the transmitted video signal. Someone skilledin the art will appreciate that other scrambling schemes may be used. Acode related to said scrambling is stored in a code storing unitconnected to said FPGA.

Alternatively, a single sound track is provided by a single sound sourceto the sound formatting unit 18, and a single video signal is providedby a single video signal to the video formatting unit 20. In suchembodiment, the transmitted video signal comprises the single soundtrack signal and the single video signal. However, in such embodiment,an encoding is performed prior the transmitting in order to avoidunauthorized reception of the transmitted signal. The signal may betransmitted using in analog or digital techniques. It will be apreciatedthat such alternative embodiment is particularly well-suited for anevent requiring a short geographic scale coverage.

1. A method for providing a plurality of video programs to a pluralityof video program receivers having a first resolution using a singlefrequency band enabling transmission of a video program having a secondresolution substantially higher than the first resolution, the methodcomprising the steps of: receiving a plurality of video programs from aplurality of video program sources, the plurality of video programshaving a resolution substantially equal to the second resolution;formatting each of the plurality of video programs received from theplurality of video program sources to have a resolution substantiallyequal to the first resolution; inserting each of the formatted videoprograms at a specific location in a main video signal having aresolution substantially equal to the second resolution; transmittingthe main video signal to each of the plurality of video programreceivers.
 2. The method as claimed in claim 1, wherein the main videosignal comprises a data signal provided by a data signal source.
 3. Themethod as claimed in claim 1, wherein four video programs are received,the main video signal being a NTSC signal.
 4. The method as claimed inclaim 1, further comprising the step of receiving a plurality of soundtracks from a plurality of sound track sources, each of the plurality ofsound tracks being attached to one of the plurality of video programs,the method further comprising the step of formatting each of theplurality of sound tracks in order to have a sound resolution compatiblewith a sound resolution of the video program receivers, the soundresolution of the video program receivers being substantially lower thanthe main video signal sound resolution, the method further comprisingthe step of inserting the formatted plurality of sound tracks in themain video signal.
 5. The method as claimed in claims 1-4, furthercomprising the step of encoding the main video signal prior saidtransmitting.
 6. The method as claimed in claim 5, wherein the encodingis performed by switching at least two lines in the main video signal.7. The method as claimed in claim 1, wherein the video program sourcesare live video signals of specific locations of a common event.
 8. Themethod as claimed in claim 2, wherein the video program sources are livevideo signals of specific locations of a common event.
 9. The method asclaimed in claim 8, wherein the common event is a live event.
 10. Themethod as claimed in claim 8, wherein the data signal source providesdata related to said event or to a participant of said event.
 11. Anapparatus for displaying at least one of a plurality of video programsignals inserted in a main video signal, the at least one of a pluralityof video program signals having a first resolution, the main signalhaving a second resolution substantially higher than the firstresolution, the apparatus comprising: a receiving unit receiving themain video signal; a user interface for enabling a user to select atleast one of the plurality of video programs contained in said mainvideo signal for a display, the user interface providing a commandsignal representative of the selected at least one of the plurality ofvideo programs to display; a display screen, receiving the selectedvideo signal for display; a processing unit receiving the main videosignal and selecting at least one part of the main video signal providedby the receiving unit according to said command signal provided by theuser interface, the selected one of the plurality of video programs todisplay being displayed on said display screen.
 12. The apparatus asclaimed in claim 11, wherein the receiving unit is receiving a pluralityof main video signals, the user interface further enabling the user toselect one of the plurality of main video signals.
 13. The apparatus asclaimed in claim 11, further comprising an audio unit, receiving anaudio signal from said receiving unit, wherein the main video signalcomprises a plurality of sound tracks signals, each of the plurality ofsound tracks signals being related to one of the plurality of videoprogram signals.
 14. The apparatus as claimed in claim 11, wherein themain video signal is encoded using a code, the apparatus furthercomprising a configuration storing unit storing said code, theprocessing unit further decoding the received main video signalaccording to said code stored in said storing unit.
 15. The apparatus asclaimed in claim 11, further comprising a remote control interface unit,the remote control interface unit being connected to said processingunit and receiving a remote control signal from a remote computer. 16.The apparatus as claimed in claim 11, wherein said first resolution issubstantially 360×240.
 17. The apparatus as claimed in claim 11, whereinsaid second resolution is 720×480.
 18. The apparatus as claimed in claim15, wherein said remote control interface unit is a serial compatibleport unit.
 19. The apparatus as claimed in claim 11, wherein saiddisplay screen is a LCD active matrix screen.
 20. An apparatus forbroadcasting at least one of a plurality of video program signalsinserted in a main video signal to a plurality of receiving units, eachreceiving unit having a first resolution, the main signal having asecond resolution substantially higher than the first resolution, theapparatus comprising: a formatting unit receiving the at least one of aplurality of video programs signals, the formatting unit formatting theat least one of a plurality of video program signals to have aresolution substantially equal to a resolution of a receiving unit, theresolution of the receiving unit being substantially lower than theresolution of the main video signal; a combining unit, receiving theformatted at least one of a plurality of video signals and incorporatingeach of the formatted at least one of a plurality of video signals intoa specific location in the main video signal; a transmitter, receivingthe main video signal and transmitting the main video signal to theplurality of receiving units.
 21. The apparatus as claimed in claim 20,wherein the formatting unit further comprises a sound track formattingunit, receiving a plurality of sound tracks signals from a plurality ofsound tracks sources having a first sound resolution, each of theplurality of sound track sources being related to one of the pluralityof video programs, and providing a plurality of converted sound tracksources having a second sound resolution substantially lower that thefirst sound resolution, the combining unit further receiving saidconverted sound tracks and incorporating said converted sound tracksinto said main video signal.
 22. The apparatus as claimed in claim 20 ,further comprising an encoding unit, the encoding unit receiving mainvideo signal and providing an encoded main video signal to saidtransmitter.
 23. A method for transmitting a video program to aplurality of video program receivers having a first resolution using asingle frequency band enabling transmission of a video program having asecond resolution substantially higher than the first resolution, themethod comprising the steps of: receiving said video program from avideo program source, the video program having a resolutionsubstantially equal to the second resolution; formatting the videoprogram received from the video program source to have a resolutionsubstantially equal to the first resolution; inserting the formattedvideo program at a specific location in a main video signal having aresolution substantially equal to the second resolution; encoding themain video signal using an encoding scheme; transmitting the main videosignal to each of the plurality of video program receivers.